1. Field of the Invention
The present invention relates to a fryer apparatus in commercial application, which includes a pulse combustor as a heat source.
2. Description of the Related Art
Fryer or deep fat frying apparatus including a pulse combustor as a heat source have widely been used in commercial cooking of food items such a french fries and breaded chicken. The pulse combustor repeats explosion and combustion at a certain cycle so as to heat cooking oil contained in a frypot with heat transmitted through a combustion chamber and a tail pipe wall. FIG. 4 is a schematic view showing a conventional fryer apparatus 100 with a pulse combustor.
The conventional fryer apparatus 100 includes: a frypot 10 which is filled with cooking liquid or oil for deep fat frying frozen food items; and a pulse combustor 11 for heating the cooking oil contained in the frypot 10. The pulse combustor 11 has a combustion-exhaust system, an air supply system, a fuel gas supply system, and an electric installation system 27 for controlling pulse combustion.
The combustion-exhaust system includes: a combustion chamber 12 disposed in the frypot 10 for pulse combustion; tail pipes 13 constituting an exhaust conduit of hot combustion byproducts from the combustion chamber 12; an exhaust decoupler 14 connecting to the tail pipes 13; and two exhaust mufflers 15, 15' coupled with the exhaust decoupler 14.
The air supply system for supplying air to the combustion chamber 12 includes: a fan 16 feeding the air for combustion; an intake muffler 17 connecting to the fan 16 in the air flow path; and an air chamber 18 coupled to the combustion chamber 12 for receiving the air fed through the intake muffler 17.
The fuel gas supply system includes: two electromagnetic valves 20, 21 for opening and closing a flow path of fuel gas supplied through a gas conduit 19; a gas governor 22 for adjusting the gas pressure; and a gas chamber 23 disposed in the air chamber 18. Elements in the air chamber 18 are drawn by the thin lines for clarification.
The fuel gas supplied into the gas chamber 23 and the air supplied into the air chamber 18 are mixed with each other in a mixing chamber 24 arranged in the intake side of the combustion chamber 12. A mixture of the air and the fuel gas is then fed into the combustion chamber 12 at which the mixture is ignited and explosively combusted. The negative pressure generated immediately after the explosion allows further admission of the fuel gas and the air for the subsequent combustion. Heat generated in such a cyclic explosion and combustion is applied through the walls of the combustion chamber 12 and the tail pipes 13 to heat cooking oil in the frypot 10.
The pulse combustor 11 is further provided with a gas flapper valve 25 and an air flapper valve 26 respectively mounted at the inlets of the fuel gas and the air into the mixing chamber 24 to prevent back flow of combustion exhaust into the gas supply system or the fuel gas supply system due to explosive combustion. These flapper valves 25, 26 close in response to the combustion pressure for preventing the back flow and open in response to the negative pressure generated immediately after the explosive combustion to feed the gas and the air to the mixing chamber 24.
In the pulse combustor 11 thus constructed, there is undesirably large noise due to opening and closing of the gas flapper valve 25 and the air flapper valve 26, along with combustion noise due to high combustion pressure. The conventional fryer apparatus 100 includes silencers for noise reduction, that is, the intake muffler 17 and the exhaust mufflers, 15, 15', which occupy relative large spaces and thereby make the fryer apparatus 100 itself undesirably large.
In the commercial cooking application, this bulky fryer apparatus makes it difficult to add some convenient man-saved functions such as a lift system for elevating and soaking food items from and into the frypot or a filtering system for cleansing used cooking oil by filtering particulate food matter from the oil drained from the frypot.